131 research outputs found
Web Auctions in Europe
No full textThis paper argues that a better understanding of the business model of web auctions can be reached if we adopt a broader view and provide empirical research from different sites. In this paper the business model of web auctions is refined into four dimensions. These are auction model, motives, exchange processes, and stakeholders. One of the objects of this research is to redefine the blurry concept of the business model by analyzing one business model, the web auction model. We show in this research the complexity and diversity of factors contributing to the success of the web auction model. By generalizing the results to the level of business model we also show how complex and diverse business models can be. Motivated by the lack of empirically grounded justification for the mixed business results of web auctions, this paper adopts a qualitative approach that includes telephone interviews with web auctions developed in different European countries.exchange processes;stakeholders;Web auctions
The Metamorphic, The Subtle and The Awkward: Three Thoughts on Indigenization
No full textThis paper highlights three occasionally overlooked aspects of Indigenization: the metamorphic, the subtle and the awkward. First, the author discusses how an epistemological shudder arising from the tension between Indigenous and non-Indigenous ways of knowing is an essential first step toward Indigenization. For the author, our Indigenization journey must begin by changing our minds and hearts. Second, the author draws on his own teaching experience toward a discussion of the subtle ways in which Indigenous knowledge can be integrated into existing lessons. The author argues that Indigenization does not have to be ostentatious as long as it is authentic. Finally, the author concludes by drawing on settler-educator Sheena Koops‘ (2018) concept of the “awkward ally.” Koops‘ awkward ally is someone who is not afraid to look silly or be proven wrong about something in the pursuit of allyship with Indigenous peoples. Whereas faculty, staff and students can sometimes be incapacitated by uncertainties or a lack of knowledge, Koops‘ concept of the awkward ally reminds us that it is okay to make mistakes as long as we are willing to learn from them. The overall message of this paper is that if we want to Indigenize our teaching, we should start with ourselves and be unafraid to make mistakes
Performance comparison between the Dutch and European signalling system at bottlenecks
No full textIn this research a comparison has been made between on one side the Dutch signalling system with ATB-EG train protection and on the other side the European signalling system ETCS Level 2. The minimum feasible headway times at bottlenecks for both systems have been compared. A selection has been made of the 22 most relevant train sequences on six often occurring infrastructure layouts. For each layout, the positioning of signals (for ATB) or block limits (for ETCS) has been sought that leads to the lowest feasible headway time for between one and four train sequences. To enable fast calculation and comparison of the headway times at different signal positionings a spreadsheet calculation model has been developed for both signalling systems. In 15 of the 22 train sequences, the European system ETCS L2 yielded a shorter headway time than the Dutch system ATB-EG. The improvements ranged from 1,1s to 21,3s, which corresponds to savings of up to 21%. In the other 7 train sequences, the headway times found in this research for ETCS L2 were higher than those that could be reached in the Dutch signalling system when applying the appropriate signal positions. When averaged over all 22 train sequences, ETCS L2 gives a 4,5% reduction of the headway time. When only averaging the 16 train sequences that don’t involve freight trains, the reduction more than doubles to an average of 9,3%. The main differences between the two signalling systems that contribute to the better performance of the European system are the fact that the braking curves are block-independent, train-dependant and speed-dependant and that there is a very low minimum block length. The research presented three types of limitations that could prevent signals from being placed on the exact location where they would be needed (level crossings, overhead section breaks and neutral overhead section breaks) and investigated the sensitivity of the found minimum headway times, which showed that the values found for ETCS L2 are much more robust and that the required block limit positionings contain much more flexibility. The results from the research were applied on the corridor Weesp – Almere Oostvaarders, showing again that ETCS would bring more buffer time increases and require less infrastructure adaptations. To improve the accuracy of future studies comparing the Dutch and European signalling systems, focus should be put on obtaining more certainty about the ETCS braking curves of the representative Dutch passenger rolling stock.Transport & PlanningCivil Engineering and Geoscience
Two new tools and a working method for crisis management of accidental spills at sea
No full textCivil Engineering and Geoscience
Creating public value: Optimizing cooperation Between public and private Partners in infrastructure Projects
No full textInfrastructure projects - such as the construction of tunnels and bridges or the (re)construction of roads and highways – are always performed to add quality to society. In The Netherlands, these projects are most often financed by the government, from local to national level, and constructed by private contractors. Public and private partners increasingly recognize the importance of cooperation to ensure successful execution of projects. However, the partnership arrangements made at strategic level are still difficult to ensure at tactical level, where the project is controlled. This study focuses on the tactical level and specifically on the perspective of the public project managers. It is investigated what they consider project success and how the project management team operates to control the project processes. The main result of this study is the public Value Chain in which the processes of the combined project organization are captured. Recommendations are made on the primary and secondary processes that binds the partners to each other. The public Value Chain will help collaborating partners to position their specific contribution to the project outcomes more clearly. Practitioners are encouraged to use the public Value Chain to organize their project activities and discuss the contribution of both public and private parent organizations to an efficient process. It can help partners to execute their specific contribution to the value they are creating. This will further optimize collaboration between public and private partners.Integral Design & Managemen
Evaluating the procurement documents of Dutch water boards portfolio: A step towards more reliable public clients
No full textAlthough a considerable amount of literature has addressed the public procurement in the construction industry, still little is known about procurement in small and repetitive activities. In practice, however, public clients are often involved in repetitive tasks such as maintenance activities. Dutch water boards, regional governmental bodies responsible for providing water management services, are the focus of this study. For this research, three main procurement documents of the water boards were performed using content analysis. The aim is to evaluate these documents and to identify the typology of the repetitive activities and the procurement volume of these tasks from a portfolio perspective of the public client. Most of the contractors/suppliers involved in these activities are local Small and Medium-Sized Enterprises (SMEs). The findings of the study indicate that insights into the typologies of these repetitive works and their expected volume over time delivers crucial value for the public procurer. Given the amount of repetitive works procured by public clients, creating such an insight to both clients as well as contractors can ultimately increase efficiency and improve investment opportunities.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Design & Construction Managemen
Ellipsometer with two lasers
No full textEllipsometer having light source means which provide a first light beam (g1) having a first angular frequency ( omega 1) and a second light beam (g2) having a second angular frequency ( omega 2), a neutral beam splitter (N) having a front face for receiving a measuring beam (g'm2), which during operation is produced by scanning a sample (S;OD1;OD2) with the second light beam (g2), and a rear face for receiving the first light beam (g1), wherein, during operation, an interference beam is formed at the rear face, wherein the light source means comprise two separate laser sources (L1, L2) and the ellipsometer is provided with a control circuit (C) having at least one input for receiving information with regard to the first and second angular frequencies ( omega 2, omega 1) or the difference between the two and at least one output, coupled to at least one of the two laser sources, for controlling the difference between the first and second angular frequencies ( omega 2, omega 1).Technology, Policy and Managemen
The Heijplaat Science Center
No full textA design for a Science Center at Heijplaat Rotterdam. An architectural design developed in a double graduation track where research has been done on building integrated systems for climate regulation and indoor comfort.Architectural EngineeringBuilding TechnologyArchitectur
Is project success a coincidence or can it be enforced? A comparative study on the critical success factors of the Stadsbrug Nijmegen project and similar civil engineering projects in the Netherlands
No full textConstruction Management and EngineeringStructural EngineeringCivil Engineering and Geoscience
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